Don't think it is a defect, I am now having issues with the 9" HF coil disconnecting throughout the day on several occasions. In fact when I first turned on the Deus, the coil wouldn't even initialise. Went through and checked that the serial number was the correct one for the coil - all good, still didn't start up. Ended up rebooting, and the coil started up this time, though several drop outs were experienced afterwards.
Never had this issue before, though noticed it seems to happen when I chose to use the remote audio vs using the WS4 controller - that is the only thing I had done differently when compared to my last several detects. My version of V4.0 was uploaded pretty much when it first came out, so will be updating all my coils again today to see if it solves the issue (and also the Mi-6 changeover issue).